High performance wrought powder metal articles and method of manufacture

Abstract

A nickel base powder metallurgy superalloy gas turbine engine disk for a compressor or turbine. The wrought powder metallurgy gas turbine engine disk has desirable fatigue crack growth resistance and a superior balance of tensile, creep rupture and low cycle fatigue strength characteristics. In one embodiment the disk defines a segregation free homogenous structure.

What is claimed is:  
     
       1. A composition consisting essentially of, in weight percent, 0.015%-0.035% carbon, 15.5%-16.5% chromium, 14%-15.5% cobalt, 2.75%-3.25% molybdenum, 4.75%-5.25% titanium, 2.25%-2.50% aluminum, 1%-1.5% tungsten, 0.030%-0.090% zirconium, 0.020%-0.030% boron, up to 0.90% hafnium, and the balance nickel plus incidental impurities. 
     
     
       2. A composition comprising in weight percent, about 0.025% carbon, about 0.020% boron, about 0.035% zirconium, about 16% chromium, about 5% titanium, about 2.5% aluminum, about 14.75% cobalt, about 3% molybdenum, about 1.25% tungsten, about 0.75% hafnium, and the balance nickel plus incidental impurities. 
     
     
       3. The composition of  claim 2 , having from about 0.035%-about 0.056% zirconium, and having from about 2.36%-about 2.50% aluminum. 
     
     
       4. The composition of  claim 3 , having about 0.056% zirconium. 
     
     
       5. A composition comprising in weight percent, about 0.025% carbon, about 0.030% boron, about 0.070% zirconium, about 16% chromium, about 5% titanium, about 2.5% aluminum, about 14.75% cobalt, about 3% molybdenum, about 1.25% tungsten, about 0.75% hafnium, and the balance nickel plus incidental impurities. 
     
     
       6. A gas turbine engine disk, comprising: 
       a main body member formed of a gamma prime strengthened wrought powder metallurgy composition consisting essentially of, in weight percent, 0.015%-0.035% carbon, 15.5%-16.5% chromium, 14%-15.5% cobalt, 2.75%-3.25% molybdenum, 4.75%-5.25% titanium, 2.25%-2.50% aluminum, 1%-1.5% tungsten, 0.030%-0.090% zirconium, 0.020%-0.030% boron, up to 0.90% hafnium, and the balance nickel plus incidental impurities; and  
       said main body member has a substantially segregation free homogenous microstructure having an average grain size within a range of about 25 microns to about 3 microns.  
     
     
       7. The gas turbine engine disk of  claim 6 , wherein said main body member has a finished diameter within a range of about four inches to about thirty-two inches and has a finished weight within a range of about four pounds to about four hundred pounds. 
     
     
       8. The gas turbine engine disk of  claim 6 , wherein said main body member microstructure has an average grain size of about 8 microns. 
     
     
       9. The gas turbine engine disk of  claim 6 , wherein said main body member microstructure has an average grain size of about 16 microns. 
     
     
       10. The gas turbine engine disk of  claim 6  which has an average grain size of about 16 microns, and wherein said main body member has been supersolvus solution heat treated at a temperature within a range of about 2130° F.-2150° F. for a length of time of about one to about four hours, followed by cooling at a rate of about 60° F./minute-about 600° F./minute to room temperature, and further followed by aging at a temperature of about 1400° F. for about eight hours and then air cooled to room temperature and aging at a temperature of about 1200° F. for about twenty-four hours and then air cooled to room temperature. 
     
     
       11. The gas turbine engine disk of  claim 6  which has an average grain size of about 8 microns, and wherein said main body member has been subsolvus solution heat treated at a temperature within a range of about 2020° F.-2065° F. for about one to about four hours, followed by cooling at a rate of about 60° F./minute-about 600° F./minute to room temperature, and further followed by aging at a temperature of about 1400° F. for about eight hours and then air cooled to room temperature and aging at a temperature of about 1200° F. for about twenty-four hours and then air cooled to room temperature. 
     
     
       12. The gas turbine engine disk of  claim 6 , wherein said wrought powder metallurgy composition consisting essentially of, in weight percent, about 0.025% carbon, about 16% chromium, about 14.75% cobalt, about 3% molybdenum, about 5% titanium, about 2.5% aluminum, about 1.25% tungsten, about 0.035%-0.056% zirconium, about 0.020% boron, about 0.75% hafnium, and the balance nickel plus incidental impurities. 
     
     
       13. The gas turbine engine disk of  claim 6 , wherein said wrought powder metallurgy composition consisting essentially of, in weight percent, about 0.025% carbon, about 16% chromium, about 14.75% cobalt, about 3% molybdenum, about 5% titanium, about 2.5% aluminum, about 1.25% tungsten, about 0.070% zirconium, about 0.030% boron, about 0.75% hafnium, and the balance nickel plus incidental impurities. 
     
     
       14. A process of preparing a nickel base powder metal superalloy gas turbine engine disk, comprising: 
       furnishing a composition consisting essentially of, in weight percent, 0.015%-0.035% carbon, 15.5%-16.5% chromium, 14%-15.5% cobalt, 2.75%-3.25% molybdenum, 4.75%-5.25% titanium, 2.25%-2.50% aluminum, 1%-1.5% tungsten, 0.030%-0.090% zirconium, 0.020%-0.030% boron, up to 0.90% hafnium, and the balance nickel plus incidental impurities;  
       consolidating the composition to produce a perform member;  
       thermomechanically working the perform to produce a wrought member; and  
       heat treating the wrought member.  
     
     
       15. The process of  claim 14 : 
       which further includes melting the composition to form an alloy melt material;  
       which further includes atomizing the alloy melt material to produce a quantity of powder metal particles of the alloy; and  
       wherein said consolidating includes at least one of vacuum hot pressing, hot isostatic pressing, hot compaction, and extrusion.  
     
     
       16. The process of  claim 15 , wherein said consolidation occurring over a temperature range of about 1950° F. to about 2125° F. 
     
     
       17. The process of  claim 14 , wherein said thermomechanically working includes at least one of extruding, forging, rolling, and co-extruding, 
     
     
       18. The process of  claim 17  wherein said thermomechanically working is defined by forging at a temperature within a range of about 1875° F. to about 2100° F., and said heat treating includes a supersolvus solution heat treatment. 
     
     
       19. The process of  claim 18 , wherein said supersolvus heat treatment is within a temperature range of about 2130° F. to about 2150° F. for about one to about four hours and said heat treating includes cooling the wrought member at a rate of about 60° F./minute to about 600° F./minute, and which further includes a two stage aging. 
     
     
       20. The process of  claim 19 , wherein said supersolvus heat treatment is occurring at about 2140° F. for about two hours and which further includes aging the wrought member after said heat treating. 
     
     
       21. The process of  claim 14  wherein said thermomechanically working is defined by forging at a temperature within a range of about 1875° F.-about 2100° F. and said heat treating includes a subsolvus solution heat treatment. 
     
     
       22. The process of  claim 21 , wherein said subsolvus heat treatment temperature is within a range of about 2020° F. to about 2065° F. for about one to about four hours and said heat treating includes cooling the wrought member at a rate of about 60° F./minute to about 600° F./minute to an ambient temperature, and which further includes a two stage aging. 
     
     
       23. The process of  claim 22 , wherein said subsolvus solution heat treating is at about 2065° F. for about two hours and which further includes aging the wrought member after said heat treating. 
     
     
       24. The process of  claim 21 , wherein said forging is occurring at about 2065° F. 
     
     
       25. The process of  claim 14 , wherein said consolidating produces a fully dense preform member. 
     
     
       26. The process of  claim 14 : 
       which further includes melting the composition to form an alloy melt material;  
       which further includes atomizing the alloy melt material to produce a quantity of powder metal particles of the alloy;  
       wherein said consolidating is defined by hot isostatic pressing within a temperature range of about 1950° F. to about 2125° F.; and  
       wherein said thermomechanically working is defined by forging.  
     
     
       27. The process of  claim 14 , wherein said consolidating includes extrusion and one of vacuum hot pressing, hot isostatic pressing and hot compaction. 
     
     
       28. A metal alloy consisting essentially of: in weight percent, 0.015%-0.035% carbon, 15.5%-16.5% chromium, 14%-15.5% cobalt, 2.75%-3.25% molybdenum, 4.75%-5.25% titanium, 2.25%-2.75% aluminum, 1%-1.5% tungsten, 0.030%-0.090% zirconium, 0.020%-0.050% boron, up to 0.90% hafnium, and the balance nickel plus incidental impurities, said metal alloy subjected to thermomechanical processing and heat treatment to produce an average grain size in the alloy of between about 3 microns and about 25 microns. 
     
     
       29. The metal alloy of  claim 28  having a supersolvus temperature level greater than about 1162° C.(2125° F.). 
     
     
       30. The metal alloy of  claim 28  having a substantially uniform microstructure. 
     
     
       31. The metal alloy of  claim 28  wherein the alloy exhibits a microstructure that is substantially free of chemical segregation. 
     
     
       32. The metal alloy of  claim 28  comprising between about 0.020%-0.030% boron. 
     
     
       33. The metal alloy of  claim 28  comprising between about 2.25%-2.50% aluminum. 
     
     
       34. The metal alloy of  claim 28  wherein thermomechanical processing comprises one or more of: extruding, forging, rolling, and co-extruding. 
     
     
       35. The metal alloy of  claim 28  having, in weight percent, between about 0.035% and about 0.056% zirconium, and between about 2.36% and about 2.50% aluminum. 
     
     
       36. The metal alloy of  claim 28  having in weight percent about 0.056% zirconium. 
     
     
       37. The metal alloy of  claim 28  comprising, in weight percent, about 0.025% carbon, about 0.030% boron, about 0.070% zirconium, about 16% chromium, about 5% titanium, about 2.5% aluminum, about 14.75% cobalt, about 3% molybdenum, about 1.25% tungsten, about 0.75% hafnium, and the balance nickel plus incidental impurities. 
     
     
       38. The metal alloy of  claim 28  formed into an article for use in a gas turbine engine. 
     
     
       39. The metal alloy of  claim 28  wherein the article is a disk.